On Mon, Aug 07, 2017 at 10:41:39AM -0700, Linus Torvalds wrote: > On Mon, Aug 7, 2017 at 9:18 AM, Maciej W. Rozycki <macro@xxxxxxxxxx> wrote: > > > > So what would be the right value of `si_code' to use here for such an > > unexpected exception condition? I think `BUG()' would be too big a > > hammer here. Or wouldn't it? > > Hell no. NEVER EVER BUG(). > > The only case to use BUG() is if there is some core data structure > (say, kernel stack) that is so corrupted that you know you cannot > continue. That's the *only* valid use. > > If this is a "this condition cannot happen" issue, then just remove > the damn conditional. It's pointless. Adding a BUG() to show "this > cannot happen" is not acceptable. I queued a patch to remove the code for 4.14. Ralf